Help me decide between 10"dob GSO vs Bresser

[astronotyet]

19 hours ago, Second Time Around said:

However, the 30mm eyepiece gives an exit pupil (aperture divided by magnification) of 6.1mm that may be too low a magnification for you.  This is because if the exit pupil is larger than the pupil of your eye you won't be seeing all the light, so effectively you'll have a smaller aperture scope

If I understood correctly, 30mm widefield won't be of much use? I struggle to understand the concept of exit pupil and how it effects the viewing. In your opinion, if I go with the Bresser, would the 25mm SuperPlössl eyepiece that comes with it, suffice or would I be missing out a lot from GSO's 30mm widefield eyepiece?

 

19 hours ago, Second Time Around said:

I think it can be summed up by saying that the GSO package is very good initial value for money, whilst the Bresser is a better design.  The difference in cost is very small, and in percentage terms will be even smaller once you've done all the upgrades that most people do.  But even after the upgrades the Bresser will still have the better mount.

19 hours ago, Second Time Around said:

Two additional factors are that it's much easier to carry the tube of the Bresser because you can use the altitude rings.  In fact you can easily carry the tube in one hand.  You can also easily rebalance the tube when adding equipment, and to a greater degree than with the GSO.

Your detailed insight is now forcing me to think this through, I am now leaning more towards the Bresser, the only thing still bugs me about Bresser is the lack of a barlow, a 9mm eyepiece and a subpar finderscope. I guess I can live without widefield 30mm eyepiece but other things do add up making the final cost much higher for me then it seems on the paper. 

The more I think, it seems like this is the major plus point of the Bresser. The weight and ease of carrying it around will be the deciding factor whether the telescope will be used a lot of collect dust. I guess I can always upgrade eyepieces and barlows later on.

Thank you so much for your valuable insight.

[astronotyet]

16 hours ago, Pixies said:

Availability might be a determining factor. Both are showing as out-of-stock on FLO just now. Bresser 60-90 working days and StellaLyra 90-120 working days.

StellaLyra is not available in India. I only have 3 options, i.e. Skywatcher(too expensive), GSO and Bresser. As per tejraj (the local vendor in India), both the GSO and Bresser will be in stock by November.

[jetstream]

9 minutes ago, astronotyet said:

I am now leaning more towards the Bresser, the only thing still bugs me about Bresser is the lack of a barlow, a 9mm eyepiece and a subpar finderscope

I would think about the telescope features you like and not so much the included accessories IMHO. A light Rigel finder is a great addition to any dob.

[johninderby]

The eyepieces included with dobs are generally not that good and are just included to give the buyer something to use until they get better quality eyepieces so don’t be concerned about any included eyepieces.

Edited September 27, 2021 by johninderby

[Second Time Around]

1 minute ago, astronotyet said:

If I understood correctly, 30mm widefield won't be of much use? I struggle to understand the concept of exit pupil and how it effects the viewing. In your opinion, if I go with the Bresser, would the 25mm SuperPlössl eyepiece that comes with it, suffice or would I be missing out a lot from GSO's 30mm widefield eyepiece?

 

Your detailed insight is now forcing me to think this through, I am now leaning more towards the Bresser, the only thing still bugs me about Bresser is the lack of a barlow, a 9mm eyepiece and a subpar finderscope. I guess I can live without widefield 30mm eyepiece but other things do add up making the final cost much higher for me then it seems on the paper. 

The more I think, it seems like this is the major plus point of the Bresser. The weight and ease of carrying it around will be the deciding factor whether the telescope will be used a lot of collect dust. I guess I can always upgrade eyepieces and barlows later on.

Thank you so much for your valuable insight.

The 30mm would still be of use as it will give a much wider field of view than the 25mm Plossl, making it easier to find objects.  However, within the smaller field of view that the Plossl covers you'll see fainter stars etc. than with the 30mm.  As I said it's swings and roundabouts.  As others have said, you'll probably eventually end up with something better, although either will do nicely for the time being.

Will you be keeping your 4 inch?  If so, which eyepieces do you already have as they might be useful, at least for the short term?

To begin with, the smaller finder on the Bresser won't be as good.  However, you'll almost certainly end up with a RACI finder whichever scope you buy.

You make a very good point about a scope gathering dust.  There's an opt-repeated saying in astronomy that says that the best scope is the one that you use!

[astronotyet]

12 minutes ago, Second Time Around said:

Will you be keeping your 4 inch?  If so, which eyepieces do you already have as they might be useful, at least for the short term?

 

Yes, the 4inch will always be my goto telescope, I currently have 2 GSO plossl eyepieces (25mm and 12mm) but no barlow. I think if I add in a decent barlow from here (if you could help me select) I won't need a smaller 9mm eyepiece for timebeing, that should suffice for some good planetary observations with the 10". 

[Second Time Around]

3 minutes ago, astronotyet said:

Yes, the 4inch will always be my goto telescope, I currently have 2 GSO plossl eyepieces (25mm and 12mm) but no barlow. I think if I add in a decent barlow from here (if you could help me select) I won't need a smaller 9mm eyepiece for timebeing, that should suffice for some good planetary observations with the 10". 

I'd recommend the inexpensive 2x GSO Barlow (in fact I have a rebranded version of it myself).  This is because by unscrewing the bottom black section and screwing that into the bottom of the eyepiece you also have a 1.5x Barlow.

This would mean that your existing12mm eyepiece could be converted into both 8mm and 6mm eyepieces.

[astronotyet]

5 minutes ago, Second Time Around said:

I'd recommend the inexpensive 2x GSO Barlow (in fact I have a rebranded version of it myself).  This is because by unscrewing the bottom black section and screwing that into the bottom of the eyepiece you also have a 1.5x Barlow.

This would mean that your existing12mm eyepiece could be converted into both 8mm and 6mm eyepieces.

Wow, I didn't know about that neat feature! Definitely getting that one 👍 

[Tiny Clanger]

10 minutes ago, astronotyet said:

Wow, I didn't know about that neat feature! Definitely getting that one 👍 

The cheaper basic skywatcher 2x barlow I own does the same,  it seems to e a standard feature on many barlows.

[Zermelo]

1 hour ago, Tiny Clanger said:

The cheaper basic skywatcher 2x barlow I own does the same,  it seems to e a standard feature on many barlows.

As does the Baader Classic Q.
Just be aware that this may not be possible with some eyepieces having designs that incorporate a "Smyth lens" in the barrel - there often isn't enough room to screw in the (part) barlow. For example, some of the BST Starguider (Astrotech Paradigm, etc.) have this feature.

[Second Time Around]

Thanks Heather, I didn't know the Skywatcher could also be used at 1.5x.

Zermelo, like you I found that the Baader Classic Q doesn't work with all eyepieces.  I therefore sold mine on.

[Second Time Around]

On 27/09/2021 at 16:11, astronotyet said:

Wow, I didn't know about that neat feature! Definitely getting that one 👍 

I'd also add that using a lower power eyepiece plus a Barlow is often more comfortable than a higher power without a Barlow.  I find that the more comfortable I am, the more I can see and the longer I can observe before getting tired.

This is because some high power eyepieces (including Plossls) have poor eye relief meaning that you have to get very close to the eyepiece, and even then you may not see the full field of view, especially if you're wearing glasses.  The lower the focal length of such eyepieces, the smaller the eye relief.  However, if using a Barlow the eye relief will be that of the longer focal length eyepiece you're using it with.  In fact, the eye relief is usually slightly longer.

Edited September 28, 2021 by Second Time Around

[spaceslug]

On 27/09/2021 at 16:26, Tiny Clanger said:

The cheaper basic skywatcher 2x barlow I own does the same,  it seems to e a standard feature on many barlows.

The Celestron 2x barlow I have also has this feature, but I never thought to use the removable bit with another eyepiece. Will have to give that a try thanks.

On 27/09/2021 at 19:49, Second Time Around said:

I'd also add that using a lower power eyepiece plus a Barlow is often more comfortable than a higher power without a Barlow.  I find that the more comfortable I am, the more I can see and the longer I can observe before getting tired.

This is because some high power eyepieces (including Plossls) have poor eye relief meaning that you have to get very close to the eyepiece, and even then you may not see the full field of view, especially if you're wearing glasses.  The lower the focal length of such eyepieces, the smaller the eye relief.  However, if using a Barlow the eye relief will be that of the longer focal length eyepiece you're using it with.  In fact, the eye relief is usually slightly longer.

That's worth knowing thanks, will be giving that a try too.